This application claims the priority of Japanese Patent Applications Nos. 6-34124 and 6-34125 filed on Feb. 7th, 1994, which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a constitution enabling recycling of given parts of a returned lens fitted photographic film unit for a film-replaceable camera.
2. Description of the Related Art
In the past, lens fitted photographic film unit (simplified cameras) have been widely adopted as disposable cameras. Such a lens fitted photographic film unit is easily available and can be handed to a developing agent as it is on completion of photography. A supplier of lens fitted photographic film unit can take back the film at the time of development. Given parts retrieved from the film are recycled as parts for a new lens fitted photographic film unit as they are.
The lens fitted photographic film unit merely feeds film unidirectionally and solely has simple components essential to photography. A film rewind mechanism is therefore not included. The housing and package of the lens fitted photographic film unit are designed to be strong enough to withstand exposures performed on one roll of film. Thus, efforts have been made to reduce manufacturing cost.
FIG. 9 shows components responsible for film feed and shutter operation in a conventional lens fitted photographic film unit. In FIG. 9, a sprocket 1 engages with perforations of film. An axis 2 of the sprocket 1 is provided with a charge cam 3 for charging a shutter with spring constraining force required for driving the shutter and a film wind stoppage cam 4 for stopping film frame by frame. A stoppage recess 5 is formed in the film wind stoppage cam 4. A drive lever 8 having a drive 7 is placed in order to cause a sector that is not shown to pivot. Shutter operation is executed when the drive 7 kicks an upper projection of the sector. The drive lever 8 is supported rotatably about an axis. An arm 10 serving as a follower that abuts on the charge cam 3 is projecting from one side surface of the drive lever 8. A spring stopper 11 is formed at a back end of the drive lever 8.
A stoppage lever 13 is supported rotatably about an axis 14, and has a first claw 15 that is fitted into the stoppage recess 5 in the film wind stoppage cam 4. An abutment 16 is attached to the bottom of the stoppage lever 13 and positioned so that it comes into contact with the front right-hand surface of a bent 18 of the drive lever 8. A spring 19 serving as a constraining member is placed as a lower member of the axis 14 of the stoppage level 13. One end of the spring 19 is anchored by a protrusive strip 20 that is a lower part of the stoppage lever 13, and the other end thereof is anchored by the spring stopper 11 of the drive lever 8. By means of the spring 19, as indicated with arrows F1 and F2, the drive lever 8 is constrained to turn counterclockwise (viewed from above) and the stoppage lever 13 is constrained to turn clockwise. The stoppage lever 13 has a second claw 21 that engages with a tooth formed along the outer circumference of a film wind knob that is not shown.
FIGS. 10A and 10B show states of actions made by the foregoing components. After release operation is completed, when film is wound in the state shown in FIG. 10A, the charge cam 3 turns counterclockwise and engages with the arm 10. This causes the drive lever 8 to turn clockwise resistively to spring constraining force. When the arm 10 passes over the maximum-diameter portion of the charge cam 3 and parts from the charge cam 3, the constraining force of the spring 19 constrains the drive lever 8 to turn counterclockwise. At this time, as shown in FIG. 10B, the bent 18 of the drive lever 8 abuts on the abutment 16 of the stoppage lever 13. Furthermore, the first claw 15 of the stoppage lever 13 is fitted into the stoppage recess 5 in the film wind stoppage cam 4 and the second claw 21 thereof is engaged with an outer-circumferential tooth of the film wind knob 22.
As mentioned above, the drive lever 8 enters a charging state. When the claws 15 and 21 of the locking lever 13 are locked, frame-by-frame stop (wind stop) is executed and the film wind knob 22 is immobilized. An acting member 23 interlocked with a shutter button (FIG. 9) is used to move the protrusive strip 20 of the stoppage lever 13 to the right in FIG. 9. The bent and abutment 16 are freed from each other, causing the drive lever 8 to turn counterclockwise in the state shown in FIG. 10B. A projection 24 formed as an upper part of a sector is then kicked by the drive 7. With the pivoting of the sector, opening and closing of a shutter is executed.
FIG. 11 shows layout in a conventional lens fitted photographic film unit permitting strobe flashing, wherein a front cover is removed. A body 101 has a viewfinder 102 and a photographing lens 103. A film stowage 104 in which unexposed film is wound up in advance is located at the right-hand end of the body 101, and a Patrone chamber 105 in which exposed film is wound about a Patrone is located at the left-hand end thereof. A film wind knob 106 for winding exposed film frame by frame is placed on the top of the Patrone chamber 105. A strobe circuit board 108 containing a strobe flashing unit 107 is mounted. A springy switch 110 for detecting the open or stop state of a shutter is extending near above the photographing lens 103. The switch 110 is turned on by a projection 111 that is interlocked with the pivoting of the sector incorporated. Furthermore, a battery 112 is placed on the bottom of the body 101. The output of the battery 112 is supplied to circuits formed on the strobe circuit board 108 via electrode terminal plates 113 and 114.
According to the foregoing layout, for executing strobe flashing, a charging switch that is not shown is used to deliver given charges from the battery 112 to a capacitor 109. After charging is completed, when the shutter button is pressed, the switch 110 detects the opening of the sector. Based on the result of the detection, flashing is executed. When the shutter is open, the strobe flashing unit 107 flashes light.
Even in the field of ordinary cameras permitting film replacement (bidirectional film feed), since there is an increasing demand for inexpensive cameras, it is required to reduce the number of component parts and the man-hours for assembly. On the other hand, if parts retrieved from aforesaid lens fitted photographic film unit can be recycled for other products rather than the lens-mounted film, the application range of retrieved parts expands. Parts retrieval will be highly appreciated. In particular, the component members responsible for film feed and shutter operation, which are described in conjunction with FIGS. 9 and 10, have relatively long service lives and complex components. These component members are therefore worth recycling. The recycling has a significant meaning in terms of cost reduction.
The circuit members responsible for strobe flashing, which are described in conjunction with FIG. 11, include a flash lamp and a capacitor, have relatively long service lives, and are worth recycling cost-wise.